Reviews & Analysis

Liquid cell electron microscopy provides a unique combination of spatial and temporal resolution, which is useful for imaging static and dynamic processes in liquids. In this Review, we discuss the resolution expected when imaging liquid specimens in transmission electron microscopy and scanning transmission electron microscopy and consider the benefits of spherical and chromatic aberration for resolution, image interpretability and dose efficiency.

3D electrodes with interconnected and interpenetrating pathways enable efficient electron and ion transport. In this Review, the design and synthesis of such 3D electrodes are discussed, along with their ability to address charge transport limitations at high areal mass loading and to enable composite electrodes with an unprecedented combination of energy and power densities in electrochemical energy storage devices.

Ingestible electronics can be used as clinical tools for diagnosis and therapy. In this Review, the authors discuss clinical applications of ingestible electronic devices and highlight materials and sensor technologies, drug delivery applications and major challenges and opportunities for clinical translation, such as safety, powering and communication.

The dynamics of epithelial tissues play a key role in tissue organization, both in health and disease. In this Review, the authors discuss materials and techniques for the study of epithelial movement and mechanics and investigate epithelia as active matter from a theoretical and experimental perspective.

Holographic duality establishes a connection between quantum gravity and strongly correlated many-body systems, providing a unique opportunity to study quantum black holes in the laboratory. In this Review, Sachdev–Ye–Kitaev models, which illustrate this duality, are discussed, along with their potential realization in ultracold gases, graphene, semiconducting nanowires and 3D topological insulators.

Combining low-dimensional and 3D perovskites is a promising approach to achieve stable and efficient solar cells. In this Review, we discuss the structural, optical and photophysical properties of low-dimensional perovskites, compare the stability and efficiency of 2D and 3D perovskite devices, and consider 2D/3D composites as a strategy to increase the stability of perovskite solar cells.

Inorganic semiconductor devices enable the formation of functional interfaces with cells and tissues to detect or provide physical stimuli. In this Review, inorganic semiconductor materials are discussed for electronic and optoelectronic sensing, optoelectronic and photothermal stimulation and photoluminescent in vivo imaging.

Sound waves can be manipulated using structurally designed 2D materials of subwavelength thickness. This emerging field, namely, acoustic metasurfaces, is driven by the desire to control acoustic wave propagation using compact devices.

Cells can be transplanted into the body to both repair injured or diseased tissue and restore tissue function. This Review discusses how biomaterial design strategies can be used to improve cell survival, influence the fate of transplanted cells, and favourably manipulate the host microenvironment and the immune system.

Graphene-integrated photonics is a platform for wafer-scale manufacturing of modulators, detectors and switches for next-generation datacom and telecom systems. This Review describes how these functions can be achieved with graphene layers placed on top of optical waveguides, acting as passive light guides, thus simplifying the current technology. In addition, a roadmap of the technological requirements for the datacom and telecom markets is presented.

A responsive material in the form of a polymer or hydrogel can be combined with a signal transduction element in the form of plasmonic particles, resulting in hybrid plasmonic polymer nanocomposites. In this Review, the fabrication and applications of such nanocomposites are discussed. The applications described focus on optical data storage, sensing and imaging and the use of photothermal gels for in vivo therapy.

There is increasing interest in the liquid, glass and amorphous solid states of coordination polymers and metal–organic frameworks. In this Review, we discuss the background and terminology of this emerging field, categorize example structures and provide an outlook for the future direction of the field.

This Review discusses how biomaterials can be used to recreate and understand the influence of specific tumour microenvironment properties on cancer progression and highlights materials-based strategies to capture, detect and assess metastatic cancer cells in vitro and in vivo.

Angle-resolved photoemission spectroscopy (ARPES) is a powerful experimental technique that can directly visualize electronic structures of materials. In this Review, the basic principles of ARPES are introduced, and its application to quantum materials, with a focus on topological quantum materials and transition metal dichalcogenides, is discussed.

The past four decades have seen breathtaking developments in techniques and applications using synchrotron radiation for the characterization of heterogeneous catalysts and catalytic processes. In this Review, we discuss recent advances, focusing on spatial and temporal explorations of the solid catalyst.

Photon spectroscopies provide insight into a wide range of materials. In this Review, theoretical and computational efforts to understand, simulate and predict the results of photon spectroscopies are assessed for systems both in and out of equilibrium, with a focus on advances that reveal information about correlated materials.

Interactions of nanoparticles with the kidneys affect their transport, clearance, targeting, therapeutic efficacy and biosafety in the body. This Review discusses nano–bio interactions of nanoparticles in the kidneys and highlights their potential for the detection and treatment of disease.

Organ-on-a-chip devices can recreate key aspects of human physiology in vitro, offering an alternative to animal models for preclinical drug testing. This Review examines how tissue barrier properties, parenchymal tissue function and multi-organ interactions can be recreated in organ-on-a-chip systems and applied for drug screening.

Heusler compounds, Weyl semimetals and the Berry phase are three current research fields of great interest. In this Review, we discuss the connection between the Berry phase and Weyl physics in the context of highly tunable Heusler compounds.

Nanoplasmonics have emerged as a promising technology for applications in life sciences and medicine. In this Review, we discuss the application of nanoplasmonic optical antennas for in vivo intracellular exploration, photonic gene delivery and regulation, and in vitro molecular diagnostics.